The Adrenal Glands and Stress Response

Anatomy and Function of Adrenal Glands

• Adrenal glands are located on top of each kidney.
• Comprised of two main parts: adrenal medulla (inner) and adrenal cortex (outer).

Hormones of the Adrenal Medulla

• Produces epinephrine (adrenaline) and norepinephrine.
• Released during emergency situations, influenced by the sympathetic nervous system.
• Both hormones play a crucial role in immediate stress response with a synergistic effect.
• Epinephrine primarily stimulates metabolic activities, bronchial dilation, and increases blood flow to skeletal muscles and the heart.
• Norepinephrine is more effective in causing peripheral vasoconstriction, contributing to elevated blood pressure.

Effects of Hormone Secretion

• Over-secretion can lead to hypertension and aggressive behavior.
• Under-secretion results in inability to respond effectively to emergencies.

Hormones of the Adrenal Cortex

• Main types produced include glucocorticoids (e.g., cortisone) and mineralocorticoids (e.g., aldosterone).
• Glucocorticoids help regulate blood glucose levels.
• Mineralocorticoids manage mineral levels in the blood.
• Both types are produced under the influence of adrenocorticotropic hormone (ACTH).

Conditions Related to Hormone Secretion

• Addison's disease results from under-secretion of cortical hormones, marked by general metabolic disturbances, muscle weakness, and loss of salts.
• Cushing's disease arises from over-secretion of cortical hormones, characterized by excessive protein breakdown leading to muscle and bone weakness.

Other Hormones

• The adrenal cortex also produces androgens, like testosterone, in small amounts for both males and females.

Test your knowledge of the adrenal glands and their role in the body's stress response. Explore the production and release of epinephrine (adrenaline) and norepinephrine, and their connection to the sympathetic nervous system.